Preheat your oven to 250 F. Wash the kale thoroughly with cold water and then pat dry. Remove the kale leaves from the tough ribs and cut into smaller pieces
Line your baking sheet with some parchment paper. In a large bowl, toss the kale with some olive oil and kosher salt, easy on the salt as a little may go a long way. Place the kale on the baking sheet in a single layer, do not overcrowd the baking sheet. Use more than one baking sheet if you need to. Roast the kale until crispy, about 35-40 minutes (with my oven anyway, check your oven as it may not take as long with yours)